I was 23-years-old the first time I was arrested. It was at the Pentagon— an act of civil disobedience in protest of the U.S. war on Vietnam. My boyfriend, Jerry Rubin, and I were organizers for the National Mobilization Committee Against the War (familiarly called The Mobe).

Here we call it the Vietnam War. The Vietnamese more accurately call it the American War. After all, the U.S. was the aggressor. It was our troops that landed on their soil; our planes that bombed their cities and sprayed Agent Orange; our army massacred their civilians, women and children included. Not the other way around.

Like many young, politically engaged Americans, I had been reluctant to protest the war, even though we understood it was immoral, because I was afraid it would interfere with my work in the civil rights movement. That changed in 1967, when both the Rev. Dr. Martin Luther King Jr. and Muhammed Ali – two towering, but very different, black leaders – denounced the war. By the fall, the civil rights and antiwar movements were converging, and 100,000 people – blackand white, old and young – were descending on Washington to protest the war.

The March on the Pentagon, which occurred 50 years ago this month, led to the arrests of 1,000 people, including myself. It brought the antiwar movement into the spotlight, and the mainstream. Drawing on the lessons of the black freedom movement, it also showed the power that everyday people can have in changing the course of our country. Now 50 years later America is once again torn by racial and social strife, and I, and millions of others, are once again organizing, marching and resisting.

Ken Burns and Lynn Novick’s recent documentary about Vietnam calls it a mistake, began by people with honorable intentions. They’re not alone.

But those of us in the core of the antiwar movement knew that the war was not a mistake. It was a crime. It was a crime against humanity that left in its wake at least 2 (some say 4) million dead Vietnamese as well as an ecosystem corrupted by Agent Orange and generations of children born with severe birth defects. In the United States 60,000 American GIs, most of them unwilling draftees, came home in body bags or with wounds that last a lifetime.

That conviction that it was a crime drove us to build a movement that quickly grew beyond the core of students, religious leaders and other activists and, ultimately, played a critical role in bringing the war to an end.

One telling example: Watching us from the roof of the Pentagon that day was a young aide to McNamara named Daniel Ellsberg. He was already having doubts about the war, but the march left a big impression on him. Ellsberg would later join our ranks (and face charges of treason) for releasing the Pentagon Papers which exposed the conspiracy of lies that kept the war going.

Many other Americans, in different positions than Ellsberg, would make the same choice after watching our activism.

Meanwhile, draft cards were burned, President Johnson quit the field, and protesters were shot down at Kent and Jackson State while we (not McNamara!) were charged with “conspiracy”.

Did we disrupt the 1968 Democratic Convention? Hell yes, we did, and “the whole world was watching.” We had a huge advantage: a growing youth counterculture disenchanted with American materialism, conformity and racism. And a generation of activists learning from the black freedom movement.

The energy of the civil rights and antiwar movement was a catalyst for other movements – gay rights, women’s rights, denuclearization, the environment. Today protest politics are a central part of our national conversation. All the while, activists have learned from their mistakes, evolved strategies and attacked new challenges with vigor.

The problem is, the other side has learned, too. Just look at what The Masters of War learned from their military defeat: eliminate the draft and keep American casualties down by using contractors, drones, and “volunteers”; ignore national borders since “terrorists” can be found anywhere and everywhere; rely on “enhanced interrogation” which beats torture because it doesn’t leave marks; ignore the laws of war and the Geneva Convention entirely. Welcome to Guantanamo!

As to winning hearts and minds, there’s no more unlimited access to TV, “embedding” only authorized journalists. They’ve waged a propaganda campaign to obliterate the “Vietnam syndrome”, a campaign that muddies the waters about who was responsible (“both sides committed atrocities”), glorifies military service, and denigrates and trivializes the anti-war movement.

Today the U.S. war machine is bigger than ever. The American military-industrial complex (Eisenhower’s words, not mine) is the most powerful killing machine in human history with a vast network of bases around the world supporting half a million military personnel— soldiers, spies, contractors and others. Secretary of Defense Robert Gates once reported “the US battle fleet is larger than the next 13 navies combined— 11 of which are our partners and allies.”

And at this moment we are faced with a new “Afghan Surge”— thousands more U.S. troops into a country that has endured 16 years of carnage with 150,000 civilians killed.

However, I see a renewal of humanity in Occupy, Black Lives Matter, the Dreamers, the Indian water protectors and their allies. I see a renewal of hope in the Town Hall meetings, the women’s marches, and the airport actions. A new generation is stirring and making the connections.

Our last great anti-war actions were in 2003, right before the Iraq invasion. Since then both parties have led us into war— Iraq, Afghanistan, Libya, Yemen and Syria. These wars are happening in our name, without debate and without our consent. This is too important to leave to the politicians. We desperately need a people’s anti-war movement, one that collaborates with the other movements of these times.

This go-round we need to be aware that the police are now more militarized than ever before. Armored personnel carriers, assault rifles, submachine guns, and SWAT teams are now readily available here at home.

I am reluctant to give specific advice to today’s activists. Just as in the ‘60s we stopped troop trains, burned draft cards and marched on the Pentagon, today’s activists are inventing their own tactics— encamping at Standing Rock, jamming airports, and taking the knee. Movement veterans like me are inspired by their actions and are joining whenever and wherever we can.

My advice is simple. When you find your voice, be brave about using it. Yes on social media but also face-to-face with your friends, family, neighbors and strangers, at schools, workplaces, places of worship, and public areas. Use your creativity and imagination to rise up and make your protest visible. Find ways to resist, occupy, defy, disrupt, and disturb. That’s how we helped end the Vietnam war. Let us not throw away this shot.